1. Field of the Invention
The present invention relates to a device control system, a device control method, and a control program which controls a device connected to a network on the basis of information constituting broadcast contents.
2. Related Art
With digital broadcasting of television, a television for digital broadcasting (to be referred to as a digital television hereinafter) has been popularized. In the digital broadcasting, not only ordinary video contents but also various multimedia data such as a still image, audio information, and character information can be included in contents. For example, contents which reflect an interaction such as a remote control input by a user on a screen and a service which controls a device on the basis of the interaction are provided from a broadcasting station.
For example, in Japanese Patent Application Laid-open (JP-A) No. 2001-333030, an operation control signal to operate an in-house device depending on program contents is delivered together with program data of a broadcast program to transmit the control signal to the in-house device at a broadcast timing of a certain scene of the program. In this manner, a system which realizes such an additional service that the temperature of an air-conditioner is increased at a shot at which a hot scene is broadcasted is provided.
In Japanese Patent Application Laid-open (JP-A) No. 2002-208899, as a means of controlling a device externally connected to a digital broadcasting receiver, a method by transmitting and receiving an XML document in which a control parameter is set is proposed.
According to digital broadcasting, a cooperation between a program and an in-house device can be realized at a limited area. However, in a form that program data and a control signal are independent as in JP-A 2001-333030, a service which issues a control instruction at an arbitrary timing in a user operation or which changes a display depending on an execution result of a control instruction or a notification content cannot be realized. In addition, in relation to JP-A 2002-208899, according to a specification on which the invention is based, a describing means used to control a device disclosed in JP-A 2002-208899 is not practically operated because a manner of interpreting a description content and a control means for controlling the in-house device are not defined. More specifically, in a case of realizing control of these in-house devices and an operation of detecting interruption from a device, control except for control in an extent depending on an implementation and a specification unique to each device to be controlled cannot be performed. For example, it is virtually impossible to realize such an operation that a list of devices which can communicate with a digital television is acquired.